Name ______Per ______
Rocket Design Lab
Can you design and build a rocket to maximize hang time in the air? How does your design change over time? How do the different designs turn out compared to yours?
Background
Goal: What are you trying to accomplish and how will you do this? What are the constants and variables in this experiment? ______
Hypothesis
Explain how your design will maximize hang time. ______
______
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Materials ______
Procedure/Methods Explain the launch process. How did we determine the water amount? What pressure was used? Explain what makes the rocket go. Diagrams and pictures are a great idea. Use the rocket notes for this.
Results Record weights and hang times for your rocket and as many others as possible.
Name and design modification or special features / Weight in grams / Best Time in seconds / Trial 1 / Trial 2Class Average (mean)
How does your rocket compare to the class average?
Analyzing and Interpreting the Results
Construct a graph to present the data in an organized way. Options include a scatter plot (weight vs time) or a bar graph (least to greatest hang time or organized in some way) Write a short statement or paragraph summarizing the graph.
______
Conclusion
a. How did your rocket perform? What worked and what didn’t? Look at your hypothesis and give specific attention to each part of it.
b. What patterns did you notice about the class rockets?
c. How did your design change over time?
d. Error analysis (Human reaction time using the stop watch. How did we minimize this problem?)
e. What are you doing with your rocket in the end? Launching at Spring Tea is extracredit. Reuse or recycling of the parts are part of the grade.
______
Spring Tea ______Recycled ______Reusable ______
Water Bottle Rockets Notes Name ______
1) Label and list the purpose of any things you used on your rocket such as fins, a nosecone, a faring, and or a parachute in a well-drawn, neat sketch of your rocket in figure 1. Also label the center of gravity of your rocket. To find the center of gravity simply balance the rocket on a fingertip to find the balance point. Include measurements in inches or cm of as many dimensions of your rocket as possible. (body height, overall height, fin length and width, diameter, nose cone length, weight etc). Make a force diagram to show what is going on in a water rocket launch in figure 2. Label using force arrows the terms. Thrust, velocity, gravity, drag, psi, action, and reaction.
Figure 1 Figure 2
2) What is psi? What does it stand for? What does it mean? (1 square inch diagram)
3) One of Newton’s Laws of motion states that for every action there is an equal but opposite reaction. How does this law relate to the motion of a rocket?
4) When is there the biggest difference in pressure between the inside and outside of the water bottle? When are the internal pressures and the external pressures (inside and outside) the bottle at equilibrium?
5) Why does a rocket work better with water in it compared to one with just air?
6) Momentum is a property of moving objects. Momentum is a combination of an object’s mass and its velocity. Which substance will have more momentum coming out of the nozzle of a rocket, air or a mixture of air and water? Why?
7) How much does your rocket weigh? ______Do you think the performance of the rocket was
affected by its weight? Explain.
8) Which type of rocket will be affected more by the wind, a heavy rocket or a light one? Why? (impressive answers use the word inertia)
9) Describe the stability of your rocket’s best flight. Did it tumble end over end or go straight? Can you think ways to improve its stability?
10) If you had more time what experiments would you like to try with water bottle rockets?
11) Draw the flight path of your rocket’s best flight. Label and explain the following on your picture:
A) Label the highest point with one or all of these terms which mean the same thing: apex, vertex, or apogee.
Label the places on the flight path where the rocket is:
B) accelerating C) has maximum gravitational potential energy and D) has reached terminal velocity on the way down. E) show somehow if the rocket tumbled through the air or had a smooth flight and
F) mention other factors that you noticed (like wind direction, or problems with the launcher)that influenced the flight.
Use simple labels like speeding up, slowing down… Acceleration can be positive (speeding up) or negative (slowing down). Gravitational potential energy is energy stored in an object due to its position (think rock perched at the edge of a cliff). Terminal velocity is the maximum speed a falling object can achieve (a skydiver speeds up to a maximum speed depending on his or her body position. This maximum speed is called terminal velocity).
12) What is the rockets velocity at the apex of its flight?
13) Sketch a graph showing the velocity of your rocket vs time. Put time on the x axis in seconds since this is the independent variable. Put velocity on y and use the words low medium and high to show how the rocket’s speed changed over time.